[pianotech] Managing agraffes was Increasing bridge height

[David Ilvedson]

I've got something like that...I think Pianotek?   I think Susan Graham wrote about using it for leveling agraffes...

David Ilvedson, RPT
Pacifica, CA  94044

----- Original message ----------------------------------------
From: "Fenton Murray" <fmurray at cruzio.com>
To: pianotech at ptg.org
Received: 3/26/2009 10:09:51 AM
Subject: Re: [pianotech] Managing agraffes was Increasing bridge height


>>I wouldn't mind a counter bore that would maintain a shoulder
>Jude,
>Here are some photos of a counter bore I had a machinist modify, solves the 
>problem.
>I had a little trouble reading the exact angle I wanted off another agraffe, 
>although I'm
>not sure there is a magic number. Anyway, I think I used about 13 degrees.
>This is for reducing the height of new agraffes while maintaining the angled 
>shoulder.
>Fenton
>----- Original Message ----- 
>From: "Jude Reveley/Absolute Piano" <juderev at verizon.net>
>To: <pianotech at ptg.org>
>Sent: Thursday, March 26, 2009 7:35 AM
>Subject: Re: [pianotech] Managing agraffes was Increasing bridge height


>> Thank you for a well reasoned response, Frank. (BTW great cap/whip 
>> post-I'm still mulling).
>>
>> Now, it is not uncommon to arrive at the proper agraffe angle somewhere at 
>> or before the border torque specification of "finger tight." My procedure 
>> has been to bring it around another 180 degrees for all the reasons 
>> mentioned in this thread, and I willingly admit this will occasionally 
>> twist me out of my own comfort zone for fear that I might be stressing the 
>> agraffe at the threads leading to all kinds of imagined catastrophies, 
>> present or future. I've used washers and counterbores but am not wholely 
>> satisfied with those techniques because of their inherent disadvantages, 
>> namely time consumption and flattening the shoulder at the base; so I'm 
>> looking for options.
>>
>> I wouldn't mind a counterbore that would maintain a shoulder. Suppliers? 
>> Listening? Jurgen? I could especially use it for those fun vintage 
>> Becksteins.
>>
>> So based on this survey, I suppose I'll stick with tight; but I'm still 
>> trying to get a sense of when is too tight. I figure if I had a spec for 
>> this limit, I could take some measurements and develop the feel. Then I 
>> can get on with it, as Ron suggested.
>>
>> As to new agraffes vs. old, for me it comes down to weighing the 
>> cost/benefit.  Polishing old ones remains more expensive than buying new 
>> ones and spending a little extra time refining the holes. I save the old 
>> ones for when this may not be the case. I borrowed my method from 
>> Paul-Flitz on a quill-like buffer in a dremel or foredom.
>>
>> Paul: Hoping you still read every post with "agraffe" in the tiltle...what 
>> are you using for a buffer? I find are q-tips too big. I made some from 
>> hammer felt scraps but am interested trying something store bought?
>>
>> Thanks,
>>
>> Jude Reveley, RPT
>> Absolute Piano Restoration, LLC
>> Lowell, Massachusetts
>> (978) 323-4545
>>
>> ----- Original Message ----- 
>> From: <pianoguru at cox.net>
>> To: <pianotech at ptg.org>
>> Cc: "Jude Reveley/Absolute Piano" <juderev at verizon.net>
>> Sent: Thursday, March 26, 2009 8:33 AM
>> Subject: Re: [pianotech] Managing agraffes was Increasing bridge height
>>
>>
>>> ---- Jude Reveley/Absolute Piano <juderev at verizon.net> wrote:
>>>> Did you interpret the use of threadlock to be in the agraffe hole or at 
>>>> the
>>>> threads. I can imagine threadlock around the agraffe threads robbing 
>>>> only as
>>>> much energy as a tuning pin bushing. How is this related to a rigid
>>>> terminus?
>>>
>>> With or without thread lock, if the agraffe is loose, ie. lacking solid 
>>> contact around the head of the stud in the counterbore, this constitutes 
>>> something less than a rigid terminus.  To suggested the possibility of 
>>> vibration of the agraffe, in itself, constitutes lack of rigidity.
>>>
>>> To suggest the use of Thread Lock is concede that potential vibration is 
>>> a legitimate concern.  To suggest a softer fomulation of Thread Lock in 
>>> the interest of serviceability is to defeat the argument for its use in 
>>> the first place.
>>>
>>> Putting aside the concerns for vibration and rigidity, do you suppose it 
>>> would be an acceptable practice to finger tighten all agraffes, and back 
>>> them off from finger-tough, to align each agraffe to an alignment 
>>> perpendicular to its speaking length(s)?  I've seen this in new piano 
>>> production.  It's not pretty.  All I'm saying is that nothing short of 
>>> tightening the agraffes beyond finger-tight, will insure a rigid terminus 
>>> and proper alignment.
>>>
>>> Frank Emerson
>>>
>>>
>>>
>>
>>
>>
>>